The fabrication of very large antennas regardless of the technology used often approaches the limits of the technology in size and leads ultimately to very high fabrication costs. Furthermore, a small error in a large antenna can result in a failure of the antenna product. This is the reason certain technology approaches that might be used in other industries cannot be readily applied to antenna fabrication. One such technology is active matrix technologies.
Active matrix technologies have been used to drive liquid crystal displays. In such technologies, one transistor is coupled to each liquid crystal cell and each liquid crystal cell can be selected by applying a voltage to a select signal coupled to the gate of the transistor. Many different types of transistors are used, including thin-film transistors (TFT). In the case of TFT, the active matrix is referred to as a TFT active matrix.
The active matrix uses addresses and drive circuitry to control each of the liquid crystal cells in the array. To ensure each of the liquid crystal cells are uniquely addressed, the matrix uses rows and columns of conductors to create connections for the selection transistors.
The use of matrix drive circuitry has been proposed for use with antennas. However, using rows and columns of conductors may be useful in antenna arrays that have antenna elements that are arranged in rows and columns but may not be feasible when the antenna elements are not arranged in that manner.
Tiling or segmentation is a common method of fabricating phased array and static array antennas to help reduce the issues associated with fabricating such antennas. When fabricating large antenna arrays, the large antenna arrays are usually segmented into LRUs (Line Replaceable Units) that are identical segments. Aperture tiling or segmentation is very common for large antennas, especially for complex systems such as phased arrays. However, no application of segmentation has been found that provides a tiling approach for cylindrical feed antennas.